Low-water alarm for steam-boilers.



Patented Aug. 2|, I900. S. L. MOYER.

LOW WATER ALARM FOR STEAM BOILERS.

(Application filed June 25, 1900.)

(N0 Model.)

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SAMUEL'L'. MOYER, OF CINCINNATI, OHIO, ASSIGNOR TO THE LUNKEN- HEIMER COMPANY, OF SAME PLACE.

LOW-WATER ALARM FOR STEAM-BOILERS.

SPECIFICATION forming part of Letters Patent No. 656,203, dated August 21, 1900.

' Application filed June 25, 1900. Serial No. 21,472. Jo model.)

To all whom it may concern: 7

Be it known that I, SAMUEL L. MOYER, a citizen of the United States, residing at Gincinnati, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Low-Tater Alarms for Boilers, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification.

My invention relates to that class of lowwater alarms for boilers which employ a tube extending into the boiler with its lower open end extending down into the water of the boiler to the low-water level and which has at its upper end a whistle communicating with said tube and so controlled that when the water reaches the low-water level the lower end of the tube is unsealed and steam passes up through the same and sounds the whistle, thus indicating that the water in the boiler has reached the low-water level and needs to be resupplied to the boiler; and it has for its object the provision of simple and efficient means in the construction of a low-water alarm that will not only act automatically when the water in the boiler reaches the danger-point, but which can be tested at any time by an inspector to ascertain that the apparatus is in working order, as required by the present laws of Ohio and Michigan, and perhaps of other States.

The novelty of my invention will be hereinafter more fully set forth, and specifically pointed out in the claims.

In the accompanying drawings, Figure 1 is a central sectional side elevation of a low-water alarm embodying my invention in working position, a portion of the boiler being also shown in section. Fig. 2 is a corresponding view of the upper part of the apparatus looking from the left of Fig. 1.

The same letters of reference are used to in.- dicate identical parts in both figures.

A represents a vertical tube whose lower end is screwed into a tubular plug B and whose lower end is tapped through the crown-sheet of the boiler O. Upon the upper end of the tube A is screwed a valve-easing D, provided with a diaphragm a, into the lower portion of which is screwed a second tube E, which upper open end of the tube E enters.

passes centrally down through the tube A, leaving an annular space I) in the tube A, around the tube E, and thence down into the boiler,where its lower open end terminates at the level of low water, (indicated by the dotted line 0,) the normal water-level being indicated by the dotted line 61. The diaphragm (1 forms three chambers e, f, and 9 Within the valve-casing, and into the chamber f the On opposite sides of the valve-casing are two horizontal exteriorly-threaded nipples h, upon which are screwed unions 2', carrying and securing in place bonnets j, interiorly threaded to receive and engage threaded valve-stems It, carrying on their inner ends valve-disks Z,which engage seated openings m through the vertical walls of the diaphragm (1. Upon the outer ends of the bonnets are screwed tubular caps n, into which the outer ends of the valve-stems is project and are squared or flattened on their ends to receive and be engaged by a removable key F, by means of which the valves are opened and closed as desired.

Upon the top of the valve-casing there is a tubular shell G, whose lower end is screwed into the top of the valve-casing and whose upper end is interiorly threaded to receive a threaded plug 0, provided with a central aperture which is flaring at its lower end. Within the shell G there is a diaphragm 10, having a central aperture to form a seat for a fusible plug H, which is inserted from the under side through the aperture in the plug 0, which it snugly fits, and has its enlarged lower end bearing upon and covering the aperture in the diaphragm 19. There is achamber 7' around the diaphragm 19 opening into an elbow extension I, Fig. 2, projecting from the shell G, and upon the upper open threaded end of said extension I is screwed the base of a whistle J of the usual or any suitable construction.

WVhen the apparatus is in use, the valve which gives access from the annular space 12 of the tube A and the chamber 6 to the chamber g is closed and the opposite valve is open, giving access through the tube E and cham-- ber f to the chamber g, and so long as the water in the boiler does not reach or extend below the danger-level c the fusible plug II cuts off communication with the whistle, as will be readily understood; but the moment the water in the boiler descends sufficiently to unseal the lower end of the tube E live steam passes up therethrough,through the chambers fand g, to the under side of the fusible plug H, whose lower end is almost instantly fused, permitting the steam to escape through the elbow I to the whistle J, which is sounded to give the alarm, and the attendant at once is notified to look after his boiler-feedingapparatus or in other ways to resupply the boiler with water. Should an inspector at any time desire to test the apparatus, he merely closes the valve between the chambersfg and opens the opposite valve, whereupon steam from the steam space of the boiler passes at once through the'annular space I) and chambers e g to the under side of the fusible plug, which is at once fused to permit steam to pass to the whistle, as before. Of course whenevera plug is fused it is removed and replaced bya new one by simply taking out the plug 0, knocking out the partially-fused plug H, reinserting a new one, and then returning the plug 0 to place, with the new fusible plug covering the aperture in the diaphragm p.

The apparatus above described and shown applied to the crown-sheet of a boiler is equally applicable to a water-column upon the side or end of the boiler, where it will act in the same manner as above described.

One of the chief advantages of my construction, aside from its cheapness of construction and efficiency of action, lies in the fact that but one opening has to be tapped into the boiler through its crown-sheet, for both of the tubes A and E are contained within that one opening.

Having thus fully described my invention, I C-laini 1. In a low-water alarm, the combination of a tube communicating at its lower end with the steam-space of a boiler, a second tube within the first-mentioned tube whose lower end is submerged in the water of the boiler and extends to the low-water level thereof, a valvecasing upon said tubes provided with two valve-controlled openings one giving ac cess from the first-mentioned tube and the other from the interior tube, a whistle carried by said valve-casing, and a fusible plug interposed between the whistle and the valvecasing, substantially as described.

2. In a low-water alarm, the combination of a tube communicating at its lower end with the steam-space of a boiler, a second tube within the first-mentioned tube whose lower end is submerged in the water of the boiler and extends to the low-water level thereof, a valve-easing upon said tubes provided with two oppositely-set valves controlling openings the one from the first-mentioned tube and the other from the interior tube, a whistle carried by said valve-casing, and a fusible plug interposed between the whistle and the valve-casing, substantially as described.

3. The herein-described low-water alarm composed of the tube A opening into the steam-space of the boiler, the tube E within the tube A extending at its lower end to the low-water level of the boiler, the valve-casing D upon the upper ends of said tubes provided with the diaphragm a forming the chambers efg, the oppositely-set valves Z with operating mechanism therefor controlling openings between the chambers e and g and f and g respectively, (the tube A opening into the chamber 6 and the tube E opening into the chamber f) the whistle J carried by the Valvecasing D, and a fusible plug covering an aperture between the chamber 1 and said whistle, substantially as described.

SAMUEL L. MOYER.

Witnesses:

OWEN N. KINNEY, EDWARD PEcK. 

